Add full stop

Co-authored-by: Stanley <[email protected]>

Author: hugovk

Doc/c-api/apiabiversion.rst

@@ -58,7 +58,7 @@ See :ref:`stable` for a discussion of API and ABI stability across versions.
    Thus ``3.4.1a2`` is hexversion ``0x030401a2`` and ``3.10.0`` is
    hexversion ``0x030a00f0``.
 
-   Use this for numeric comparisons, e.g. ``#if PY_VERSION_HEX >= ...``
+   Use this for numeric comparisons, e.g. ``#if PY_VERSION_HEX >= ...``.
 
    This version is also available via the symbol :data:`Py_Version`.